msdos partition table.... bad? ok? (understanding parted output)

emailbuilder88 · 04-30-2010, 02:40 PM

Hello,

I am looking at a RHEL system built by a windows admin and parted output tells me the partition table is msdos format (I guess?). I am uncertain if this could be a problem (is it like formatting a disk in WinXP as old DOS format instead of NTFS? will it fail to support large files? or is this completely different?). Sorry if this should be in the newbie forum(?). Here is the parted output (I think the error about /dev/md0 is because that's the RAID 1 device - is that OK to ignore?):

Code:

parted -l
Error: Unable to open /dev/md0 - unrecognised disk label.                 

Model: Compaq Smart Array (cpqarray)
Disk /dev/cciss/c0d0: 500GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End    Size   Type     File system  Flags
 1      32.3kB  107MB  107MB  primary  ext3         boot 
 2      107MB   500GB  500GB  primary               lvm

pixellany · 04-30-2010, 02:50 PM

Quote:

I am looking at a RHEL system built by a windows admin....

Say no more--you are in big trouble.....

Seriously (to the extent that's possible on Friday afternoon):
The format of the partition table is pretty much standard. If I am not mistaken in goes back to the earliest days of the "PC". (Which of course was synonymous with msdos.)

Assuming you are running on RHEL, please post the results of these commands (running as root):

fdisk -l
cat /etc/fstab
mount

emailbuilder88 · 04-30-2010, 03:00 PM

Quote:

Originally Posted by pixellany

Say no more--you are in big trouble.....

Quote:

Originally Posted by pixellany

Seriously (to the extent that's possible on Friday afternoon):
The format of the partition table is pretty much standard. If I am not mistaken in goes back to the earliest days of the "PC". (Which of course was synonymous with msdos.)

Ah, OK. So then most people see that? Good. I hadn't ever used parted, and now that I go do the same thing on some other systems, I see they are all "msdos". OK. Whew. (in fact, is there rhyme or reason to using parted versus fdisk, etc? Sorry this is a newbie question...)

Quote:

Originally Posted by pixellany

Assuming you are running on RHEL, please post the results of these commands (running as root):

fdisk -l

Code:

fdisk -l

Disk /dev/cciss/c0d0: 500.0 GB, 500074307584 bytes
255 heads, 63 sectors/track, 60797 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Quote:

Originally Posted by pixellany

cat /etc/fstab

Code:

cat /etc/fstab 
/dev/VolGroup00/LogVol01 /                       ext3    defaults        1 1
LABEL=/boot             /boot                   ext3    defaults        1 2
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
/dev/VolGroup00/LogVol00 swap                    swap    defaults        0 0

Quote:

Originally Posted by pixellany

mount

Code:

 mount
/dev/mapper/VolGroup00-LogVol01 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/cciss/c0d0p1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)

THANK YOU for such a quick reply!

pixellany · 04-30-2010, 03:07 PM

OK--LVM

But it's on some kind of RAID?

parted shows partitions on /dev/cciss/c0d0, but fdisk does not? I'd check that again...

Do we know the physical configuration?---i.e. Do you know how many physical drives there are and whether there is in fact a RAID?

emailbuilder88 · 04-30-2010, 03:09 PM

Although my specialty is certainly not linux partition management, it seems like this is a fairly standard setup, yeah? parted complains about /dev/md0, but nowhere else does it show up, so I assume parted just doesn't know about RAID setups.

If I'm correct, it looks like this is a 500GB drive that was just dumped into a LVM volume in its entirety (yikes). I'd like to partition it up a little bit; should I just resize the LVM volume and create a new LVM volume next to it and not worry about fdisk/parted to create physical partitions?

If I start messing with physical partitions or LVM volumes, will any changes I make get reflected automatically on the RAID 1 mirror in the machine?

Thanks again!

emailbuilder88 · 04-30-2010, 03:11 PM

Oops, I replied too quickly. Didn't see your response.

Quote:

Originally Posted by pixellany

OK--LVM

But it's on some kind of RAID?

Yes, RAID 1, although I don't know much about the hardware (assuming it's not software RAID, maybe there's a way to figure that out?)

Quote:

Originally Posted by pixellany

parted shows partitions on /dev/cciss/c0d0, but fdisk does not? I'd check that again...

Hmmm, how would one go about that?

Quote:

Originally Posted by pixellany

Do we know the physical configuration?---i.e. Do you know how many physical drives there are and whether there is in fact a RAID?

Yes, it's supposedly set up with two 500GB hard disks in RAID 1.

THANK YOU!

emailbuilder88 · 04-30-2010, 03:15 PM

Sorry, my fdisk output wasn't complete. It shows that same device:

Code:

fdisk -l

Disk /dev/cciss/c0d0: 500.0 GB, 500074307584 bytes
255 heads, 63 sectors/track, 60797 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

           Device Boot      Start         End      Blocks   Id  System
/dev/cciss/c0d0p1   *           1          13      104391   83  Linux
/dev/cciss/c0d0p2              14       60797   488247480   8e  Linux LVM

pixellany · 04-30-2010, 03:18 PM

That's a relief!!

So, you've got LVM on a RAID---is it working OK?

emailbuilder88 · 04-30-2010, 03:40 PM

Quote:

Originally Posted by pixellany

That's a relief!!

So, you've got LVM on a RAID---is it working OK?

Well, it's a brand new system, nothing much going on with it yet... but sure, it seems fine. Anything specific you are thinking or just wondering why I posted here? :-)

I'm just trying to size up this machine, make sure all is in order, and then figure out how to best partition the drive (see my earlier post on this thread).

pixellany · 04-30-2010, 03:45 PM

Don't read too much into my comment---I may have simply forgotten the original question.....

My only serious comment is that I don't like RAID or LVM---they just make me think too much. I also know how to do long division---kinda just one of those weird people.....

emailbuilder88 · 04-30-2010, 03:53 PM

OK thank you!

I think it might be best to start a new thread with my partitioning questions with a more appropriate title.

Thanks again